Although each of us has engaged in a range of women, peace and security (WPS)-related work, our most immediate point of connection is that we each have acted as NGO policy advocates in the WPS policy space of the UN Security Council: sam cook, from 2005 to 2010 for the Women's International League for Peace and Freedom as the PeaceWomen Project Director and Louise Allen as the Executive Director Coordinator of the NGO Working Group on WPS from 2014– 2018. The contours of this policy space have shifted profoundly across the nine years of our combined experience – many of these changes are quite explicitly addressed by this volume. In this conversation we focus on the role of NGOs and some of the challenges of working in coalition in this particular space. The role of NGOs in policy formation (especially in relation to the adoption of UNSCR 1325) has been widely acknowledged, but the nature of ongoing engagement has received quite limited attention. As the body of WPS policy has expanded and developed, many feminist critiques of WPS policy have treated unsatisfactory policies as indicative of a failure in NGO representation. A common accusation is that those who occupy positions as NGO representatives in the policy space have been coopted or have abandoned their commitment to feminist principles (cook, 2018). Here we think through what NGO engagement involves, the risks of co-optation, and the challenges and rewards of working in feminist coalition.